1 files changed, 43 insertions, 0 deletions
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
new file mode 100644
index 000000000..ea7848e74
--- /dev/null
+++ b/include/scsi/scsi_tcq.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SCSI_SCSI_TCQ_H
+#define _SCSI_SCSI_TCQ_H
+
+#include <linux/blkdev.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#define SCSI_NO_TAG	(-1)    /* identify no tag in use */
+
+
+#ifdef CONFIG_BLOCK
+/**
+ * scsi_host_find_tag - find the tagged command by host
+ * @shost:	pointer to scsi_host
+ * @tag:	tag
+ *
+ * Note: for devices using multiple hardware queues tag must have been
+ * generated by blk_mq_unique_tag().
+ **/
+static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
+		int tag)
+{
+	struct request *req = NULL;
+	u16 hwq;
+
+	if (tag == SCSI_NO_TAG)
+		return NULL;
+
+	hwq = blk_mq_unique_tag_to_hwq(tag);
+	if (hwq < shost->tag_set.nr_hw_queues) {
+		req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
+					blk_mq_unique_tag_to_tag(tag));
+	}
+
+	if (!req || !blk_mq_request_started(req))
+		return NULL;
+	return blk_mq_rq_to_pdu(req);
+}
+
+#endif /* CONFIG_BLOCK */
+#endif /* _SCSI_SCSI_TCQ_H */